We intend to first resolve previous conflicting reports that patients with diabetes mellitus are more prone or less prone to osteopenia or fractures and second, to extend previous reports from our laboratory concerning profound disturbances of bone cell function in diabetes. We will study the bone status of patients with diabetes mellitus by photon absorptiometry, radiographic morphometry and tetracycline labelled iliac bone biopsies. Bone histology will also be studied in the amputated lower limb bones of diabetics and non-diabetics with vascular disease. The results will be compared with accurate assessment of the clinical and biochemical type and severity of the diabetic state and measurement of growth hormone, insulin, glucagon, parathyroid hormone and 25-hydroxycholecalciferol.